Drop accession workaround when nextstrain/augur 1384 is solved

[joverlee521]

Originally from #28 (comment)

[j23414]

A related #36 (comment) about "accession", "genbank_accession" and "url" so that we can hopefully group these changes in a PR.

[genehack]

@joverlee521 @j23414 do we still need this issue? I'm having trouble understanding the context from the linked issues — if this is still relevant, could somebody please update the description to more directly indicate what changes need to be made?

[j23414]

Can close this issue as we've dropped the "set_final_strain_name.py" script entirely during #72

I took a quick check and both "accession" and "USVI" links work in the node call out.